Thanks - that program worked great. Once it had created the playlist, I was able to open it in a text editor and view it, and saw that it references the drives in the following way. The first song is from the Fuze internal drive, the 2nd song is on my SDHC card:
/mmc:0:/MUSIC/T/Tame Impala - I Don’t Really Mind.mp3
/mmc:1:/Music//P/Porcupine Tree/2009 - The Incident/07 - Your Unpleasant Family.mp3
The playlist creator creates two files when you save it - one with a .PLA extension and the other with a .PLA.REFS extension. Mine created the following files when I saved a playlist named ‘Test List’:
The .PLA is empty - zero length. The .PLA.REFS file contains the songs in the above format. The above two lines showing the path to the MP3s are the entire contents of the PLA.REFS file that the program created - there is no header.
I tried reproducing the playlist as an M3U file but wasn’t able to get it to work - I tried removing the initial slashes, reversing the direction of the slashes (from ‘/’ to ‘’), but nothing I tried worked. It looks like they have to be in PLA format with the PLA.REFS file containing the songs as described.
Hope this info is useful to those who want to combine songs from different sources into a single playlist. If anyone needs me to clarify anything, let me know. Thanks Black-Rectangle for your help, it solved my problem and is greatly appreciated.